A tremendous number, such as several tens of thousands, of wire cords are utilized, for example, in the electrical systems of various equipment of an aircraft, and the wire cords have various, such as ten or more kinds, of outer diameters.
In order to prevent erroneous connection or trouble when such numerous wire cords are installed, identification displays such as schema numbers or symbols for the wires or wire cords on the basis of a manual are applied, and the wiring work is performed in accordance with the identification displays.
However, the wire cords have various diameters and, for example, include those each having a diameter of about 1 mm and also include twisted wires. Accordingly, special printing techniques are required for printing on such fine wire cords.
Heretofore, as shown in FIG. 7 as a schematic view, a type a is set and heated, and, by means of this type a, printing is carried out under pressure on a coating material d of a cord c through an ink ribbon b. In another method, the ink jet method, electric charges are applied to particles of an ink in accordance with the shapes of types preliminarily programmed, and these shapes of types are adsorbed on a printing surface
However, in both of the above conventional methods, the printing is carried out for one cord per one operation. Accordingly, when it is necessary to carry out the printing on cords of various kinds or diameters in accordance with their usages and equipment to be used, extremely troublesome or difficult work is involved in changing printing contents, adjusting many items of equipment such as cord reels, cord guides and printing units and so on. Such troublesome work may not be a significant problem in the case of a relatively smaller number of kinds of wire cords, but in the case of extremely many kinds of wire cords such as in the equipment of an aircraft, it is considerably difficult to print different kinds of identification displays on these numerous members of wire cords.